(a) Field of the invention
The present invention relates to an electronic tuning apparatus to be appropriately used for tuning various musical instruments, for example, such as a wood instrument, a brass instrument, a string instrument and a percussion instrument etc. on the basis of the scale according to the equal temperament and the scale according to any temperament other than the equal temperament.
(b) Description of the prior art
A tuning apparatus for a musical instrument, which is proposed in a prior art, is generally based on the equal temperament scale and, generally classified, an electronic type and a mechanical type are known for it.
As to an electronic tuning apparatus, such an apparatus is known, which is capable of displaying an agreement of frequency between a reference frequency signal and a tone signal to be tuned in a single display, while a reference frequency signal corresponding to a specified pitch is generated by designating an octave and a tone name with a switch etc.
Further, as to a mechanical tuning apparatus, such an apparatus is known, which is capable of displaying a stationary stroboscopic pattern for each tone name in the corresponding display window at the moment of tuning by making twelve stroboscopic pattern discs rotate at a number of revolution corresponding to the equal temperament through a gear mechanism by a synchronous motor driven by an output of a quartz oscillator, while twelve display windows are provided on a panel corresponding to twelve tone names, twelve stroboscopic pattern discs are arranged rotatably at the backside of the panel corresponding to each of the display windows and luminous elements, which turn on and off corresponding to the frequency of a tone to be measured, are provided.
In the above-mentioned electronic tuning apparatus, there is a problem that it takes a lot of time and labor for changing-over an octave and a tone name by a switch etc. when tuning is performed by changing an octave and a tone name successively and it takes a lot of time until a display of the above-mentioned agreement is performed because it takes time for the measurement of an input signal and the calculation of the average period of an input signal even if a tone signal to be measured is inputted at the same time with the change-over.
On the other hand, in the above-mentioned mechanical tuning apparatus, there is not such an above-mentioned problem as found in the electronic tuning apparatus because display sections for twelve tone names are always ready for displaying the tuning, but there is a problem that it can not respond to a scale other than the equal temperament (for example, just intonation) unless a gear ratio of a gear mechanism is changed and further that it is heavy-weighted, large-sized, inconvenient for handling and expensive due to mechanical type.